import math

class Number():
    def __init__(self, n1, n2):
        self.n1 = n1
        self.n2 = n2

    def addition(self):
        total = self.n1 + self.n2
        return total

    def subtration(self):
        result = self.n1 - self.n2
        return result

    def multiplication(self):
        result = self.n1 * self.n2
        return result

    def division(self):
        if self.n2 == 0:
            print("分母不能为除数")
        else:
            result = self.n1 / self.n2
            return result

number = Number(8,4)
print(number.addition())
print(number.subtration())
print(number.multiplication())
print(number.division())